David thomas



. @atten ,gisten gstent @fitta Lette-s Patent No. 80,575, dated August 4, 186s.

IMPROVEMENT I-"I'RITION-NIPPBR.

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TO ALL WHOM IT MA-Y CONCERN: l

Be it known that I, DAVID THOMAS, of Hinghamfin the county of Plymouth, and State of Massachusetts, have invented anilmproved Nipper-Feed for vessels windlasses and other rotatingb'odies; and I Ido hereby declare that the fol-lowing, taken inv connection with the drawings which accompany and form partof this speciication, is a description of my invention suicient to enable those skilled in the art to practise it.

This invention, though specially designed and adapted for rotating vessels windlassesis also applicable to rotate various other cylindrical bodies and wheels, and itmay be considered as an improvement on the windlassgear known as the Scotch nipper, with reference to which it will be described.

In the drawings- I Figure 1 shows in section the Scotch nipper, a being the ring which is secured to the windlass-body, and on which the nipper operates to turn the windlass-body, the section ot' the ring a being shown in Figure 2.

The nipper ispmade up of two parts or cheeks, `which are vbolted together, and are capable of sliding upon the outer flange of the ring a, the cheeks having jaws which adjoin the inner surface. ofthe outer flange.

BetweenA the cheeks b, and pivoted thereto, is a lever, c, the short end of which is eccentric to the pivot of the lever, so that as the long arm of the 4lever is lifted, the lever turns on its'pivot, bringing the eccentric or inclined end of the lever upon the outer surface ofthe outer Ailange of the ring a, causing thejaws vof the nippel" to hug closely to the inner surface of the outer flange of said ring, thus griping or clamping the ring by thel nipper, so that further movement di' the lever in an upward direction causes the ring to turn onits axis, carrying with it the windlass to which the ring is fixed. l

4When the lever is pushed downward, it will Yhe evident that it will turn slightly on-its pivot, such turning slacking the hold of the nipper onthe windlass-r'ingfso that the whole of the nipper, cheeks, and lever, will gravitate` downward, sliding on and around the out-er flange of ring a.

Now the objections to this well-known nipper, which it is the object of my invention to avoid, are these:

First. The short-end of the lever wears a groove in the outer surface of the flange of the ring a, and the` place of contact of said end of the lever being small, this also wears rapidly, so/that the apparatus very Vsoon needs repairs, which have to be accomplishedpither by making a new lever or by reforging its short end.

Second.' Great care has to be paid to the proportions of the short end ofuthe lever, for if its ecceutricity is too great, it will not gripe with'suilicient power, and the nipper will slip under stress, and if the eccentricty is too small, it takes considerable movement of the longarm ofthe lever to obtain a gripe, which, when obtained, is not easily loosened, andvery slight wear of the parts willrender the nipper wholly inoperative.

Now my invent-ion consists in making a groove, fork, orcrotch in the short arm of the-lever, and in applying a sh'oe which extends across the'outer faceA of the outer flange of'ringa, so lthat the crotch of the yshort arm of the le'vei` shall operate on the shoe, as seen-in Figure 3, which is a sectional view similar to tig.l 1,

In this tlg. 3, the conformation of the short arm ofthe lever is clearly shown, its crotchvor fork fitting on the shoe d, which extends acrossthe outer `flange of the ring a, and fits loosely'iiito shallow depressions made in the inner surfaces of the-cheeks b, so that the shoe isheld in proper position for the action thereon of the lever c; t I l I It will be obvious that by the use of the shoe extending entirely across the outer surface ofthe outer flange of ring-a, the wearing-surface is greatly increased in area, and Athat no groove can be worn by theactionof the improved nipper into the ring a. As the movement of the crotch ofthe lever on the apex of the shoe is very slight, the wenn :1t-that point will lbe almost imperceptible, and it will be readily sc en that the .gripe of the improved nipperis certain, and is obtained andrreleased with but slight vibration of lever con its pivot e, while the power of the gripe obtained will be in exact ratio to the distance from pivot e of the apex of the shoe, as

- compared to the length of the long arm of thelever.

When, after long and severe use, .wear enough takes place to produce considerableV lost motion of the long arm of the lever in-obtaining a gripe, the difficulty is easily remedied .by placing in the nipper-jaws a new and slightly thicker shoe, or for temporary purposes al thin piece of sheet metal may be inserted between the erot'oh of the'lever and the apex zof the shoe.

Figure shows a common method of working a. ships windlass by the application of'a Scotch nipper," operated by a. brake-lever, my improvement being also capable of being operated in the same manner, as well as variously otherwise. A Y

-I claim, in frietion-'npper feeds', the employment of a shoe in connection with the notehedlever, cheeks,

and flanged ring, so' as to operate substantially as described;

'. DAVID THOMAS,

Witnesses:

J. B. CRosBY, C. WARREN BROWN. 

